Julgoldite-(Fe2+)
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
About Julgoldite-(Fe2+)
Formula:
Ca2Fe2+Fe3+2[Si2O6OH][SiO4](OH)2(OH)
Colour:
Deep black, greenish black to green in small fragments
Lustre:
Sub-Metallic
Hardness:
4½
Specific Gravity:
3.58 - 3.60
Crystal System:
Monoclinic
Member of:
Name:
Named for its relationship to julgoldite-(Fe3+).
Julian Royce Goldsmith (26 February 1918, Chicago, Illinois, USA - 23 January 1999, USA), geochemist at the University of Chicago. He was an expert on feldspars and carbonates. He also served as president of the Geochemical Society, the Mineralogical Soeciety of America, and the Geological Society of America.
Julian Royce Goldsmith (26 February 1918, Chicago, Illinois, USA - 23 January 1999, USA), geochemist at the University of Chicago. He was an expert on feldspars and carbonates. He also served as president of the Geochemical Society, the Mineralogical Soeciety of America, and the Geological Society of America.
Unique Identifiers
Mindat ID:
2120
Long-form identifier:
mindat:1:1:2120:9
GUID
(UUID V4):
(UUID V4):
2c52adce-a588-4a83-9e50-525b178e851c
IMA Classification of Julgoldite-(Fe2+)
Approved
IMA Formula:
Ca2Fe2+Fe3+2(Si2O7)(SiO4)(OH)2 · H2O
Classification of Julgoldite-(Fe2+)
9.BG.20
9 : SILICATES (Germanates)
B : Sorosilicates
G : Sorosilicates with mixed SiO4 and Si2O7 groups; cations in octahedral [6] and greater coordination
9 : SILICATES (Germanates)
B : Sorosilicates
G : Sorosilicates with mixed SiO4 and Si2O7 groups; cations in octahedral [6] and greater coordination
58.2.2.1
58 : SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups
2 : Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in [6] and higher coordination; single and double groups (n = 1, 2)
58 : SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups
2 : Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in [6] and higher coordination; single and double groups (n = 1, 2)
14.22.8
14 : Silicates not Containing Aluminum
22 : Silicates of Fe and Ca
14 : Silicates not Containing Aluminum
22 : Silicates of Fe and Ca
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Symbol | Source | Reference |
---|---|---|
Jul-Fe2+ | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Jul | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Julgoldite-(Fe2+)
Sub-Metallic
Transparency:
Transparent
Colour:
Deep black, greenish black to green in small fragments
Streak:
Greenish olive with a bluish tinge
Hardness:
4½ on Mohs scale
Tenacity:
Very brittle
Cleavage:
Perfect
{100} and {001}
{100} and {001}
Density:
3.58 - 3.60 g/cm3 (Measured) 3.56 g/cm3 (Calculated)
Optical Data of Julgoldite-(Fe2+)
Type:
Biaxial (-)
RI values:
nα = 1.776(4) nβ = 1.814(4) nγ = 1.836 - 4.000
2V:
Measured: 50° to 70°, Calculated: 73°
Max Birefringence:
δ = 0.060 - 2.224
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Very High
Pleochroism:
Strong
Comments:
X = pale brown; Y = pale brownish green; Z = deep emerald-green.
Chemistry of Julgoldite-(Fe2+)
Mindat Formula:
Ca2Fe2+Fe3+2[Si2O6OH][SiO4](OH)2(OH)
Crystallography of Julgoldite-(Fe2+)
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 8.922(4) Å, b = 6.081(3) Å, c = 19.432(9) Å
β = 97.60(6)°
β = 97.60(6)°
Ratio:
a:b:c = 1.467 : 1 : 3.196
Unit Cell V:
1,045.02 ų (Calculated from Unit Cell)
Z:
4
Morphology:
fan-shaped, plumose crystal groups; granular.
Twinning:
Twin plane {001}, typically repeated, common.
Comment:
Space Group: A2/m:
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
2.958 Å | (100) |
2.780 Å | (80) |
2.574 Å | (80) |
1.519 Å | (80) |
4.817 Å | (70) |
3.859 Å | (70) |
2.501 Å | (60) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 3a: Earth’s earliest Hadean crust | >4.50 |
8 : Mafic igneous rocks | |
Near-surface Processes | |
22 : Hydration and low-𝑇 subsurface aqueous alteration (see also #23) |
Type Occurrence of Julgoldite-(Fe2+)
Place of Conservation of Type Material:
Swedish Museum of Natural History, Stockholm, Sweden; Harvard University, Cambridge, Massachusetts, 109641, 109642; National Museum of Natural History, Washington, D.C., USA, 137014.
Geological Setting of Type Material:
hematite-magnetite ore
Associated Minerals at Type Locality:
Other Language Names for Julgoldite-(Fe2+)
Russian:Джулголдит-Fe2+
Relationship of Julgoldite-(Fe2+) to other Species
Member of:
Other Members of this group:
Julgoldite-(Fe3+) | Ca2Fe3+Fe3+2[Si2O6OH][SiO4](OH)2O | Mon. |
Julgoldite-(Mg) | Ca2MgFe3+2[Si2O6OH][SiO4](OH)2(OH) | Mon. |
Forms a series with:
Common Associates
Associated Minerals Based on Photo Data:
20 photos of Julgoldite-(Fe2+) associated with Calcite | CaCO3 |
13 photos of Julgoldite-(Fe2+) associated with Prehnite | Ca2Al2Si3O10(OH)2 |
5 photos of Julgoldite-(Fe2+) associated with Pectolite | NaCa2Si3O8(OH) |
4 photos of Julgoldite-(Fe2+) associated with Fluorapophyllite-(K) | KCa4(Si8O20)(F,OH) · 8H2O |
4 photos of Julgoldite-(Fe2+) associated with Pumpellyite Subgroup | Ca2XAl2[Si2O6(OH)][SiO4](OH)2A |
2 photos of Julgoldite-(Fe2+) associated with Gonyerite | (Mn2+,Mg)5Fe3+(Fe3+Si3O10)(OH)8 |
2 photos of Julgoldite-(Fe2+) associated with Greenockite | CdS |
2 photos of Julgoldite-(Fe2+) associated with Quartz | SiO2 |
2 photos of Julgoldite-(Fe2+) associated with Datolite | CaB(SiO4)(OH) |
2 photos of Julgoldite-(Fe2+) associated with Chalcedony | SiO2 |
Related Minerals - Strunz-mindat Grouping
9.BG. | Shuiskite-(Cr) | Ca2Cr3+Cr3+2[Si2O6OH][SiO4](OH)2O |
9.BG. | Alnaperbøeite-(Ce) | Ca(Ce2.5Na0.5)(AlAl2Al)[Si2O7][SiO4]3O(OH)2 |
9.BG. | Magnesiovesuvianite | Ca19MgAl4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
9.BG. | Alumovesuvianite | Ca19AlAl4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(OH)9 |
9.BG. | Zoisite-(Pb) | (CaPb)(AlAlAl)O[Si2O7][SiO4](OH) |
9.BG. | Vielleaureite-(Ce) | (Mn2+Ce)(MgAlMn2+)F[Si2O7][SiO4](OH) |
9.BG. | Heflikite | (CaCa)(AlAlSc)O[Si2O7][SiO4](OH) |
9.BG. | Zilbermintsite-(La) | (CaLa5)(Fe3+Al3Fe2+)[Si2O7][SiO4]5O(OH)3 |
9.BG.05b | Allanite-(Ce) | (CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH) |
9.BG.05b | Allanite-(La) | (CaLa)(AlAlFe2+)O[Si2O7][SiO4](OH) |
9.BG.05b | Allanite-(Y) | (CaY)(AlAlFe2+)O[Si2O7][SiO4](OH) |
9.BG.05a | Clinozoisite | (CaCa)(AlAlAl)O[Si2O7][SiO4](OH) |
9.BG.05b | Dissakisite-(Ce) | (CaCe)(AlAlMg)O[Si2O7][SiO4](OH) |
9.BG.05 | Dollaseite-(Ce) | (CaCe)(MgAlMg)F[Si2O7][SiO4](OH) |
9.BG.05a | Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
9.BG.05a | Hancockite | (CaPb)(AlAlFe3+)O[Si2O7][SiO4](OH) |
9.BG.05 | Khristovite-(Ce) | (CaCe)(MgAlMn2+)F[Si2O7][SiO4](OH) |
9.BG.05a | Mukhinite | (CaCa)(AlAlV3+)O[Si2O7][SiO4](OH) |
9.BG.05a | Piemontite | (CaCa)(AlAlMn3+)O[Si2O7][SiO4](OH) |
9.BG.05 | Piemontite-(Sr) | (CaSr)(AlAlMn3+)O[Si2O7][SiO4](OH) |
9.BG.05b | Manganiandrosite-(La) | (Mn2+La)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
9.BG.05 | Tweddillite | (CaSr)(Mn3+AlMn3+)O[Si2O7][SiO4](OH) |
9.BG.05b | Ferriallanite-(Ce) | (CaCe)(Fe3+AlFe2+)O[Si2O7][SiO4](OH) |
9.BG.05 | Niigataite | (CaSr)(AlAlAl)O[Si2O7][SiO4](OH) |
9.BG.05 | Manganiandrosite-(Ce) | (Mn2+Ce)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
9.BG.05 | Dissakisite-(La) | (CaLa)(AlAlMg)O[Si2O7][SiO4](OH) |
9.BG.05 | Vanadoandrosite-(Ce) | (Mn2+Ce)(V3+AlMn2+)O[Si2O7][SiO4](OH) |
9.BG.05 | Uedaite-(Ce) | (Mn2+Ce)(AlAlFe2+)O[Si2O7][SiO4](OH) |
9.BG.05a | Epidote-(Sr) | (CaSr)(AlAlFe3+)O[Si2O7][SiO4](OH) |
9.BG.05b | Allanite-(Nd) | (CaNd)(AlAlFe2+)O[Si2O7][SiO4](OH) |
9.BG.05b | Unnamed (Mg-analogue of Ferriallanite-(Ce)) | (CaCe)(Fe3+AlMg)O[Si2O7][SiO4](OH) |
9.BG.05b | Unnamed (Mn3+-analogue of Ferriakasakaite-(Ce)) | (CaCe)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
9.BG.05b | Ferriallanite-(La) | (CaLa)(Fe3+AlFe2+)O[Si2O7][SiO4](OH) |
9.BG.05b | Åskagenite-(Nd) | (Mn2+Nd)(AlAlFe3+)O[Si2O7][SiO4]O |
9.BG.05 | Piemontite-(Pb) | (CaPb)(AlAlMn3+)O[Si2O7][SiO4](OH) |
9.BG.05b | Vanadoallanite-(La) | (CaLa)(V3+AlFe2+)O[Si2O7][SiO4](OH) |
9.BG.05 | Ferriandrosite-(La) | (Mn2+La)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
9.BG.05 | Androsite-(Ce) | (Mn2+Ce)(AlAlMn2+)O[Si2O7][SiO4](OH) |
9.BG.05a v | Unnamed (Ga-analogue of Epidote) | (CaCa)(AlAlGa3+)O[Si2O7][SiO4](OH) |
9.BG.05b | UM1989-32-SiO:AlCaFeHREE | (Ca0.5◻0.5REE)(AlAlFe3+)O[Si2O7][SiO4](OH) |
9.BG.05b | Manganiakasakaite-(La) | (CaLa)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
9.BG.05b | Ferriakasakaite-(Ce) | (CaCe)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
9.BG.9.BG. | Ferriakasakaite-(La) | (CaLa)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
9.BG.9.BG. | Ferriandrosite-(Ce) | (Mn2+Ce)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
9.BG.9.BG | Ferriperbøeite-(Ce) | CaCe3(Fe3+Al2Fe2+)[Si2O7][SiO4]3O(OH)2 |
9.BG.10 | Zoisite | (CaCa)(AlAlAl)O[Si2O7][SiO4](OH) |
9.BG.15 | Macfallite | Ca2Mn3+3(SiO4)(Si2O7)(OH)3 |
9.BG.15 | Sursassite | Mn2+2Al3(SiO4)(Si2O7)(OH)3 |
9.BG.20 | Okhotskite | Ca2Mn2+Mn3+2[Si2O6OH][SiO4](OH)2(OH) |
9.BG.20 | Pumpellyite-(Fe2+) | Ca2Fe2+Al2(Si2O7)(SiO4)(OH,O)2 · H2O |
9.BG.20 | Pumpellyite-(Fe3+) | Ca2Fe3+Al2(Si2O7)(SiO4)(OH,O)2 · H2O |
9.BG.20 | Pumpellyite-(Mg) | Ca2MgAl2(Si2O7)(SiO4)(OH)2 · H2O |
9.BG.20 | Pumpellyite-(Mn2+) | Ca2Mn2+Al2(Si2O7)(SiO4)(OH)2 · H2O |
9.BG.20 | Shuiskite-(Mg) | Ca2MgCr3+2[Si2O6OH][SiO4](OH)2(OH) |
9.BG.20 | Julgoldite-(Fe3+) | Ca2Fe3+Fe3+2[Si2O6OH][SiO4](OH)2O |
9.BG.20 | Pumpellyite-(Al) | Ca2Al3(Si2O7)(SiO4)(OH,O)2 · H2O |
9.BG.20 | Poppiite | Ca2V3+V3+2[Si2O6OH][SiO4](OH)2O |
9.BG.20 | Julgoldite-(Mg) | Ca2MgFe3+2[Si2O6OH][SiO4](OH)2(OH) |
9.BG.25 | Ganomalite | Pb9Ca5Mn(Si2O7)4(SiO4)O |
9.BG.25 | Wayneburnhamite | Pb9Ca6(Si2O7)3(SiO4)3 |
9.BG.30 | Rustumite | Ca10(Si2O7)2(SiO4)(OH)2Cl2 |
9.BG.35 | Vesuvianite | Ca19Fe3+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(OH)9 |
9.BG.35 | Wiluite | Ca19MgAl4(Al,Mg)8(B,◻)4◻[Si2O7]4[(SiO4)10]O(O,OH)9 |
9.BG.35 | Manganvesuvianite | Ca19Mn3+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(OH)9 |
9.BG.35 | Fluorvesuvianite | Ca19Fe3+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(F,OH)9 |
9.BG.35 | Cyprine | Ca19Cu2+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
9.BG.35 | Hongheite | Ca19Fe2+Al4(Fe3+,Mg)8(◻4)B[Si2O7]4[(SiO4)10]O(OH,O)9 |
9.BG.35 | Milanriederite | (Ca18[REE])Fe3+Al4(Mg4Al4)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
9.BG.35 | Manaevite-(Ce) | (Ca13Ce4[H2O]2)Mg(Al3Mg)(Mg3Ti3Fe3+2)(◻4)◻[Si2O7]4[(SiO4)8(H4O4)2]O(OH)9 |
9.BG.40 | Vyuntspakhkite-(Y) | (Y,Yb)4Al2.5-1.5(Si,Al)1.5-2.5(SiO4)4O(OH)7 |
9.BG.45 | Dellaite | Ca6Si3O11(OH)2 |
9.BG.50 | Gatelite-(Ce) | CaCe3(AlAl2Mg)[Si2O7][SiO4]3O(OH)2 |
9.BG.50 | Perbøeite-(Ce) | CaCe3(AlAl2Fe2+)[Si2O7][SiO4]3O(OH)2 |
9.BG.50 | Ferriperbøeite-(La) | CaLa3(Fe3+Al2Fe2+)[Si2O7][SiO4]3O(OH)2 |
9.BG.50 | Perbøeite-(La) | CaLa3(AlAl2Fe2+)[Si2O7][SiO4]3O(OH)2 |
9.BG.55 | Västmanlandite-(Ce) | CaCe3(MgAl2Mg)[Si2O7][SiO4]3F(OH)2 |
9.BG.60 | Radekškodaite-(La) | (CaLa5)(Al4Fe2+)[Si2O7][SiO4]5O(OH)3 |
9.BG.60 | Radekškodaite-(Ce) | (CaCe5)(Al4Fe2+)[Si2O7][SiO4]5O(OH)3 |
9.BG.60 | Radekškodaite Group | (CaM5)([Fe3+Al3]Fe2+)[Si2O7][SiO4]5O(OH)3 |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Julgoldite-(Fe2+)
mindat.org URL:
https://www.mindat.org/min-2120.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Julgoldite-(Fe2+)
Localities for Julgoldite-(Fe2+)
Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Germany | |
| 70. +1 other reference |
| Walenta (1992) |
| Poser et al. (2004) |
| Weiß (1990) |
| Weiß (1990) |
| Grütze (2006) |
India | |
| Wise and Moller (1990) |
| Fabre Minerals |
Italy | |
| Gamboni (2003) |
Japan | |
| Matsubara et al (1992) |
Norway | |
| Brastad (1982) +1 other reference |
Sweden (TL) | |
| Moore (1967) +2 other references |
Moore (1967) +2 other references | |
| Nysten (2004) |
Ukraine | |
| Karpenko V. (New Data on Minerals) +1 other reference |
USA | |
| Van Nostrand Reinholt Press: 493 +2 other references |
| Martins da Pedra specimen +1 other reference |
Quick NavTopAbout Julgoldite-(Fe2+)Unique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Rauschermühle Quarry, Niederkirchen, Otterbach-Otterberg, Kaiserslautern, Rhineland-Palatinate, Germany